CAD/CAM LAB REPORT FILE
SUBMITTED TO Prof. Mohammed Suhaib (Dept. of Mechanical Engg.) Jamia Millia Islamia Submitted by Md.Azheruddin B.Tech (Mech.) 8th Semester 08-MES-37
CAD/CAM LAB REPORT
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INDEX Exp.NO Name of Experiment Date Signature To study the open CIM setup of 23/01/12 1 2 3 4 5
6
automation and CIM lab To study the anatomy of Robotic Arm 06/02/12 ER-5 And Er-7 To study and operate the CNC Lathe 27/02/12 and CNC vertical milling machine To study and operate the PLC 05/03/12 controler and oval type conveyer belt To write and run the CNC program for the Lathe Machine for the given 9/04/12 drawing using CNC train simulator To write and run the CNC program for the Milling Machine for the given drawing using CNC train simulator
CAD/CAM LAB REPORT
9/04/12
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EXPERIMENT NO-1 Object:- To study the open CIM setup of automation and CIM lab. Equipments Required:- CNC machines, Robots, PlC’s, AS/RS, Computers, Conveyors etc.
Layout:Pneumatic Pipeline
Feeders
Station 2
Station 1
VSRS
ROBOT ER-VII
MOTOR
ROBOT ER-V
PLC
CNC Mill
CNC Lathe
Air Compressor
STATION-1 PC
CIM Manager
CONVEYOR
STATION-2 PC
Lath e PC
Working of CIM:- Typically, a work piece, which is located at the ASRS, will be placed on the conveyor system by a gantry robot. The conveyor will transport the work piece to the CNC milling machine where another robot will pick up the work piece from the conveyor belt and place it in the machine. After the milling process, the robot will return it to the conveyor belt where another robot will pick up the work piece and place it in the CNC lathe machine. After the work piece has been machined, it will be transported by the conveyor belt to the assembly station for assembly and QC check. If the work piece is satisfactory, it will then be bar coded at the next station and CAD/CAM LAB REPORT
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Mill PC
transported to the ASRS for inventory purpose. The whole process is controlled by a Central Management Control Station (CMCS), which sends the exact instructions to the various stations for the work to be performed. The conveyor belt serves as a transport highway where the work piece will be loaded and sent on to its destination.
1. Automatic Storage and Retrieval System (ASRS) 2. CNC Lathe Machine 3. CNC Milling Machine 4. Robots 5. Assembly/Quality Control Station 6. Closed Loop Conveyor System 7. Barcode Scanning System 8. Central Management Control Station (CMCS)
Theory:- Computer-integrated manufacturing (CIM) is the manufacturing approach of using computers to control the entire production process. The term "computerintegrated manufacturing" is both a method of manufacturing and the name of a computer-automated system in which individual engineering, production, marketing, and support functions of a manufacturing enterprise are organized. In a CIM system functional areas such as design, analysis, planning, purchasing, cost accounting, inventory control, and distribution are linked through the computer with factory floor functions such as materials handling and management, providing direct control and monitoring of all the operations. ELEMENTS OF CIM SYSTEM 1. Marketing: The need for a product is identified by the marketing division. The specifications of the product, the projection of manufacturing quantities and the strategy
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for marketing the product are also decided by the marketing department. Marketing also works out the manufacturing costs to assess the economic viability of the product. 2. Product Design: The design department of the company establishes the initial database for production of a proposed product. In a CIM system this is accomplished through activities such as geometric modeling and computer aided design while considering the product requirements and concepts generated by the creativity of the design engineer. The design process creates the database required to manufacture the part. 3. Planning: The planning department takes the database established by the design department and enriches it with production data and information to produce a plan for the production of the product. Planning involves several subsystems dealing with materials, facility, process, tools, manpower, capacity, scheduling, outsourcing, assembly, inspection, logistics etc. 4. Purchase: The purchase departments is responsible for placing the purchase orders and follow up, ensure quality in the production process of the vendor, receive the items, arrange for inspection and supply the items to the stores or arrange timely delivery depending on the production schedule for eventual supply to manufacture and assembly. 5. Manufacturing Engineering: Manufacturing Engineering is the activity of carrying out the production of the product, involving further enrichment of the database with performance data and information about the production equipment and processes. In CIM, this requires activities like CNC programming, simulation and computer aided scheduling of the production activity. 6. Factory Automation Hardware: Factory automation equipment further enriches the database with equipment and process data, resident either in the operator or the equipment to carry out the production process. In CIM system this consists of computer controlled process machinery such as CNC machine tools, flexible manufacturing systems (FMS), Computer controlled robots, material handling systems, computer controlled assembly systems etc. 7. Warehousing: Warehousing is the function involving storage and retrieval of raw materials, components, finished goods as well as shipment of items. In today’s complex outsourcing scenario and the need for just-in-time supply of components and subsystems, logistics and supply chain management assume great importance.
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8. Finance: Finance deals with the resources pertaining to money. Planning of investment, working capital, and cash flow control, realization of receipts, accounting and allocation of funds are the major tasks of the finance departments. 9. Information Management: Information Management is perhaps one of the crucial tasks in CIM. This involves master production scheduling, database management, communication, manufacturing systems integration and management information systems.
Advantages of CIMS: 1. Increased machine utilization 2. Reduced direct and indirect labor 3. Reduce mfg. lead time 4. Lower in process inventory 5. Scheduling flexibility QUESTION AND ANSWERS Q1. Name any 5 CAM softwares? Ans. CATIA, Dynavista, Edgecam, SolidCam, WorkNC, Powermill Q2. What are the various material handling systems? Ans. (i) AGV (ii) Robots (iii) AS/RS Q3. Name any 5 CAD softwares? Ans. AutoCAD, 3D-Max, Solid Works, Unigraphics, Maya, PRO-E Q4. Broadly CNC machining centers are classified into how many types? Ans. (i) Vertical axis machining centers (ii) Horizontal axis machining centers Q5. What is the function of Machine Control Unit (MCU)? Ans. CNC part program is executed by the MCU to achieve the final component design.
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EXPERIMENT NO-2 Object: -To study the anatomy of Robotic Arm ER-5,ER-7 Equipments Required: - Scorbot ER-5,Scorbot ER-7 teach pendant Specifications:SCORBOT-ER V plus Specifications Number of Axes Axis Movement Axis 1: Base rotation Axis 2: Shoulder rotation Axis 3: Elbow rotation Axis 4: Wrist pitch Axis 5: Wrist roll Maximum Operating Radius End Effectors
5 axes plus servo gripper
Maximum Gripper Opening
75 mm (3") without rubber pads 65 mm (2.6") with rubber pads 12VDC servo motors 15 oz. in Peak Torque (stall) 70 W Power for Peak Torque Motors 1, 2, 3: 127.1:1 Motors 4, 5: 65.5:1 Motor 6 (gripper) 19.5:1 ±0.5 mm (0.02") at TCP (tip of gripper 600 mm/sec (23.6"/sec) 11.5 kg (25 lb)
Actuators Motor Capacity (axes 1–6) Gear Ratios
Position Repeatability Maximum Path Velocity Weight
CAD/CAM LAB REPORT
310° +130° / –35° ±130° ±130° Unlimited (mechanically); ±570° (electrically) 610mm (24.4")
DC servo gripper, with optical encoder, parallel finger motion; Measurement of object’s size/gripping force by means of gripper sensor and software.
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ER-5 robot
SCORBOT-ER VII Specifications Number of Axes Axis Movement Axis 1: Base rotation Axis 2: Shoulder rotation Axis 3: Elbow rotation Axis 4: Wrist pitch Axis 5: Wrist roll Maximum Operating Radius End Effectors options Actuators Transmission Position Repeatability Weight Maximum Path Velocity Maximum Payload Ambient Operating Temperature
CAD/CAM LAB REPORT
5 axes plus gripper 250°; 310° user programmable 170° 225° 180° 360° 690 (27.2") at flange Pneumatic and DCServo 12VDC servo motors Harmonic drives; timing belts and pulleys ±0.2 mm (0.008") 30 kg (66 lbs) 1000 mm/sec (39.4"/sec) 2 kg (4.4 lb.), including gripper 2°–40°C (36°–104°F)
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Figure: SCORBOT-ER VII Robot Arm
Theory:Types of Robots:1. Cartesian Coordinate Robot (also called linear robot) is an industrial robot whose threeprincipal axes of control are linear (i.e. they move in a straight line rather than rotate) and are atright angles to each other. Among other advantages, this mechanical arrangement simplifies theRobot control arm solution. Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called Gantry robots. Used for pick and place work, application of sealant, assembly operations, handling machine tools and arc welding. 2. Spherical Coordinate Robot is a robot with two rotary joints and one prismatic joint. Spherical robots have an arm which forms a spherical coordinate system. Used for handling at machine tools, spot welding, diecasting, fettling machines, gas welding and arc welding. It's a robot whose axes form a polar coordinate system. 3. Cylindrical Coordinate Robot has two linear axes and one rotary axis. The robot derives its name from the operating envelope.The Z axis is located inside the base, resulting in a compact end-of-arm design that allows the robot to "reach" into tight work envelopes without sacrificing speed or repeatability.Used for assembly operations, handling at machine tools, spot welding, and handling at diecasting machines. 4. Articulated Robot is a robot with rotary joints. Articulated robots can range from
simple two-jointed structures to systems with 10 or more interacting joints. They are powered by a variety of means, including electric motors.Used for assembly operations, fettling machines, gas welding, arc welding and spray painting. It's a robot whose arm has at least three rotary joints. 5. SCARA Robot: SCARA stands for Selective Compliant Assembly Robot Arm or Selective Compliant Articulated Robot Arm. By virtue of the SCARA's parallel-axis joint layout, the arm is slightly compliant in the X-Y direction but rigid in the ‘Z’ direction, hence the term:Selective Compliant.The second attribute of the SCARA is the jointed two-link arm layout similar to our human arms, hence the often-used term, CAD/CAM LAB REPORT
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Articulated. SCARA's are generally faster and cleaner than comparable Cartesian systems.Used for pick and place work, application of sealant, assembly operations and handling machine tools. Basic Components of a Robot:1.Manipulatorwhich is the robot’s arm, consists of segments jointed together with axes capable of motion in various directions allowing the robot to perform work. 2. End Effector which is a gripper tool, a special device, or fixture attached to the robot’s arm, actually performs the work. 3. Power supply provides and regulates the energy that is converted to motion by the robot actuator, and it may be electric, pneumatic, or hydraulic. 4. Controller initiates, terminates, and coordinates the motion of sequences of a robot. Also it accepts the necessary inputs to the robot and provides the outputs to interface with the outside world. Teach Pendant: The teach pendant is an optional device. The teach pendant (TP) is a hand-held terminal, used for controlling the robot andaxis connected to controller. The teach pendant is most practical for moving the axes, recording positions, sending the axes to recorded positions, and activating programs. Otherfunctions can also be executed fromthe teach pendant.The teach pendant has 30 functionkeys. Many of thecommand keys on the teach pendant are ACL commands.
QUESTION AND ANSWERS
Q1. Which type of robot is also called as Gantry Robots? Ans. Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called Gantry robots.
Q2. What are the basic types of clamping mechanism used in grippers? Ans. (i) Mechanical clamping (ii) Magnetic clamping (iii) Vacuum clamping
Q3. What is the workspace/ work envelope of a robot? Ans. It is the maximum volume that a robot can reach mechanically.
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Q4. What are the applications of SCARA Robot? Ans.Used for pick and place work, application of sealant, assembly operations and handling machine tools.
Q5. What are the types of motion controls used in robots? Ans. (i) Axis limit
(ii) Contouring (iii) Point-to-Point(iv) Line tracking
EXPERIMENT NO. 03 OBJECT: - To study and operate the CNC Lathe and CNC vertical milling machine. EQUIPMENT: - PLC controller, CNC Lathe and CNC vertical milling machine etc. SPECIFICATION:Main Specification Of Vertical CNC milling nachine(DENFORD STAR MILL) Accuracy resolution Max. Drilling diameter Max.End- Milling diameter Max.Surface-Milling diameter spindle speed Z Axis BallScrew X- Axis BallScrew Y- Axis BallScrew CAD/CAM LAB REPORT
0.01mm 13mm 16mm 30mm High speed：100~2500 r.p.m ±10% low speed：100~1100 r.p.m ±10% 16mm dia×5 mm pitch 10mm dia×4 mm pitch 10mm dia×4 mm pitch Page 11
Cross Travel Head Travel Electric Power ( LxWx H)overall dimension Net/gross weight
90mm 115 mm 50/60Hz-1 Phase 220/240V 8A Spidle Moter 875 × 800 × 800mm 100kg
Main Specification Of CNC Lath machine (DENFORD STARTURNER) positioning accuracy or resolution max swing diameter over bed max workpiece length max turning diameter spindle speed(infinitely adjuested spindle hole diameter X-axis ballscrew Z-axis ballscrew feed rate Distance between centers Electrical power Stepeer motors net/gross weight overall dimension(LxWxH)
CAD/CAM LAB REPORT
0.01mm 140mm 250mm 70mm 0-2000rpm 10mm 8 mm Ø2.5 mm 10mm Ø4 mm X:1100mm/min，Z：1100mm/min 250mm 1 phase 220/240 volts 6Amp spindle moter 200steps/rev dc 70kg 660 × 425 × 430mm
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Working of vertical CNC milling Machine Computer Numerical Control (CNC) Milling is the most common form of CNC. CNC mills can perform the functions of drilling and often turning. CNC Mills are classified according to the number of axes that they possess. Axes are labeled as x and y for horizontal movement, and z for vertical movement, as shown in this view of a manual mill table. A standard manual light-duty mill (such as a Bridgeport™) is typically assumed to have four axes:
1. Table x. 2. Table y. 3. Table z. 4. Milling Head z High speed CNC Milling The number of axes of a milling machine is a common subject of casual "shop talk" and is often interpreted in varying ways. We present here what we have seen typically presented by manufacturers. A five-axis CNC milling machine has an extra axis in the form of a horizontal pivot for the milling head, as shown below. This allows extra flexibility for machining with the end mill at an angle with respect to the table. A sixaxis CNC milling machine would have another horizontal pivot for the milling head, this time perpendicular to the fifth axis. CNC milling machines are traditionally programmed using a set of commands known asG-codes. G-codes represent specific CNC functions in alphanumeric format. Working of CNC lathe Machine CAD/CAM LAB REPORT
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The VICE: This holds the material to be cut or shaped. Material must be held securely otherwise it may 'fly' out of the vice when the CNC begins to machine. Normally the vice will be like a clamp that holds the material in the correct position. The GUARD: The guard protects the person using the CNC. When the CNC is machining the material small pieces can be 'shoot' off the material at high speed. This could be dangerous if a piece hit the person operating the machine. The guard completely encloses the the dangerous areas of the CNC. The CHUCK: This holds the material that is to be shaped. The material must be placed in it very carefully so that when the CNC is working the material is not thrown out at high speed. The MOTOR: The motor is enclosed inside the machine. This is the part that rotates the chuck at high speed. The LATHE BED: The base of the machine. Usually a CNC is bolted down so that it cannot move through the vibration of the machine when it is working. The CUTTING TOOL: This is usually made from high quality steel and it is the part that actually cuts the material to be shaped.
THEORY Computer Numerical Control (CNC) is one in which the functions and motions of a machine tool are controlled by means of a prepared program containing coded alphanumeric data. CNC can control the motions of the work piece or tool, the input parameters such as feed, depth of cut, speed, and the functions such as turning spindle on/off, turning coolant on/off. Applications The applications of CNC include both for machine tool as well as non-machine tool areas. In the machine tool category, CNC is widely used for lathe, drill press, milling machine, grinding unit, laser, sheet-metal press working machine, tube bending machine etc. Highly automated machine tools such as turning center and machining center which change the cutting tools automatically under CNC control have been developed. In the non-machine tool category, CNC applications include welding machines (arc and resistance), coordinate measuring machine, electronic assembly, tape laying and filament winding machines for A CNC system consists of three basic components 1. Part program 2. Machine Control Unit (MCU) 3. Machine tool (lathe, drill press, milling machine etc) A Flow DIAGRAM OF CNC
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Question answer related to CNC machine Q. No.1. What is CNC? Ans:- Computer Numerical Control (CNC) is one in which the functions and motions of a machine tool are controlled by means of a prepared program containing coded alphanumeric data. Q.NO.2 What is the application of CNC? Ans: - The applications of CNC include both for machine tool as well as non-machine tool areas. In the machine tool category, CNC is widely used for lathe, drill press, milling machine, grinding unit, laser, sheet-metal press working machine, tube bending machine etc. Q.No. 3. What is the advantage of CNC ? Ans:- The benefits of CNC are as follows – (1) high accuracy in manufacturing, (2) short production time, (3) greater manufacturing flexibility, (4) reduced human error.
Q.No.4.What is the element of CNC ? ANS;- A CNC system consists of three basic components which is given below 1 . Part program 2 . Machine Control Unit (MCU) 3 . Machine tool (lathe, drill press, milling machine etc) Q.No. 5 What is CNC control panal ? Ans :- A CNC machine is normally controlled by a computer and software.
However, most CNC machines have a range of controls for manual use.
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EXPERIMENT NO. 04 OBJECT: -To study and operate the PLC controler and oval type conveyer belt system EQUIPMENT: - PLC controller, Oval conveyer belt , air filter etc. SPECIFICATION:- Specification of oval type conveyer belt
Theory CAD/CAM LAB REPORT
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Automatic Conveyor Automatic Conveyor for Industrial Automation consists of two object sensors, rpm sensor, and rpm control circuit which controls the speed of the motor driving the conveyor. The object sensors which detect the objects sends signal to the motor driving circuit to on/off the motor. It work on the elecric pulses as electronic puces is given it move and again it stopped at requred position according to the PLC to load the work piece and work material PROGRAM LOGIC CONTROL (PLC) Control engineering has evolved over time. In the past humans were the main method for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logical control decisions. The development of low cost computer has brought the most recent revolution, the Programmable Logic Controller (PLC). The advent of the PLC began in the 1970s, and has become the most common choice for manufacturing controls. PLCs have been gaining popularity on the factory floor and will probably remain predominant for some time to come. Most of this is because of the advantages they offer. • Cost effective for controlling complex systems. • Flexible and can be reapplied to control other systems quickly and easily. • Computational abilities allow more sophisticated control. • Trouble shooting aids make programming easier and reduce downtime. • Reliable components make these likely to operate for years before failure. PLC Connections When a process is controlled by a PLC it uses inputs from sensors to make decisions and update outputs to drive actuators, as shown in Figure 1. The control loop is a continuous cycle of the PLC reading inputs, solving the ladder logic, and then changing the outputs. Like any computer this does not happen instantly. Figure 2 shows the basic operation cycle of a PLC. When power is turned on initially the PLC does a quick sanity check to ensure that the hardware is working properly. If there is a problem the PLC will halt and indicate there is an error. For example, if the PLC power is dropping and about to go off this will result in one type of fault.
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Figure 1 -The Separation of Controller and Process
Figure 2- The Scan Cycle of a PLC
Ladder diagram: Ladder logic is the main programming method used for PLCs.Ladder diagrams are the most commonly used diagrams for nonelectronic control circuits. They are sometimes called elementary diagrams or line diagrams. Two types of ladder diagrams are used in control system: the control ladder diagram and the power ladder diagram. The control ladder diagram has two active functional lines. Some of the common practices for the format of control ladder diagram are illustrated by this figure. Those practices are as follows:
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Compressed Air Filters Air filter are use to remove the dirt and dust from air so that only pure air is supplied to the syste normoly used air filter is Ballston compressed air filters which remove 99.99% of 0.01 micron particles of oil, water, and dirt from compressed air and other gases. The liquid releases from the filter cartridge to an automatic drain as rapidly as it enters the filter. This allows the compressed air filter to continue removing liquids without loss of efficiency or flow capacity. Q.No.1. On which logic first PLC program was design ? Ans :- The first PLCs were programmed with a technique that was based on relay logic wiring schematics. This eliminated the need to teach the electricians, technicians and engineers how to program a computer - but, this method has stuck and it is the most common technique for programming PLCs today. Q.No. 2. Give two example of where a PLC could be used ? Ans:- In conveyer belt and CNC PLC are used to control the motion and task. Q.No. 3. Why would relays be used in place of PLCs Ans:- for some cases is simple and cost effective relay be used in place of PLCs Q.No 4. How many types of Ladder Logic in plc ? Ans: In ladder logic there are multiple types of outputs, but these are not consistently available on all PLCs. Some of the outputs will be externally connected to devices outside the PLC, but it is also possible to use internal memory locations in the PLC. Q.No 5. Write the component of PLC . Ans;- The PLC has three components; 1) Central Processing Unit CPU, 2) Inputs, 3) Outputs.
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EXPERIMENT NO-5
Object:- To write and run the CNC program for the Lathe Machine for the given drawing using CNC train simulator Equipments Required:- Computer, CNC lathe Machine
Theory:- A Part Program is a list of coded instructions which describes how the designed part, or component, will be manufactured. This part program is also called the CNC File. These coded instructions are called data - a series of letters and numbers. The part program includes all the geometrical and technological data to perform the required machine functions and movements to manufacture the part. The part program can be further broken down into separate lines of data, each line describing a particular set of machining operations. These lines, which run in sequence, are called blocks. A block of data contains words, sometimes called codes. Each word refers to a specific cutting/movement command or machine function. The programming language recognized by the CNC, the machine controller, is an International Standards Organisation code, which includes the G and M code groups. Each program word is composed from a letter, called the address, along with a number.
Motion Command Codes:G CODES:- Set preparatory machine functions such as rapid transverse mode, feed
mode and active tool length offsets. M CODES:- Perform a miscellaneous machine function such as automatic tool changes, coolant control and spindle operations.
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Types of Formats:1. Tab Sequential Format 2. Fixed Format 3. Word Address Format PROGRAM BLOCK
Sequence Number (N)
Preparatory Word (G)
Tool Selection (T)
Spindle Speed (S)
Miscellaneous Command (M)
Coordinates (X-Y-Z)
Feed Rate (F)
End of Block (E.O.B)
For Example:- N10 GOO X30 Z-20 F10 S200 T01 M30
Steps in Programming:1. Start- work piece zero point, cutting speed, feed, spindle rotation, speed limit 2. Facing 3. Roughing
Process
4. Cutting 5. Close- stop spindle, stop coolant, program stop
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FIGURE
PROGRAM:-
N01 G59 X0 Z210 N02 G96 V200 T0202 M03 N03 G92 S2000 M08 N04 G00 X20 Z0 N05 G01 X-1 Z0 F0.2 N06 G00 X20 Z0 N07 G71 P80 Q90 I0.2 K0.2 D2 F0.2 N08 G26 N09 N80 N10 G46 N11 G00 X0 Z0 N12 G01 X4 Z0 CAD/CAM LAB REPORT
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N13 G01 X4 Z-15 N14 G02 X8 Z-20 R10 N15 G01 X8 Z-35 N16 G03 X-18 Z-45 R15 N17 G01 X-18 Z-50 N18 G40 N19 G26 N20 G96 V200 T0101 M04 N21 G92 S2000 M08 N22 G00 X20 Z-51.5 N23 G01 X14 N24 G00 X15 N25 G01 X10 N26 G00 X11 N27 G01 X6 N28 G00 X7 N29 G01 X2 N30 G00 X3 N31 G01 X0 N32 G26 N33 M5 M9 N34 M0 CAD/CAM LAB REPORT
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QUESTION AND ANSWERS
Q1. What is the meaning of G00, G01, G02? Ans. G00- Positioning in Rapid G01-Linear Interpolation G02- Circular Interpolation (CW)
Q2. What does M03, M04 stands for? Ans. M03-Spindle on (clockwise rotation) M04-Spindle on (counterclockwise rotation) Q3. Generally the CNC programming is written in which format? Ans. (a) Word Address Format (b) APT format Q4. What is the function of HOME command? Ans. Pressing the X,Y or Z key will send the machine to its home position along the selected axis. Q5. What is the function of DATUM command? Ans. Pressing the X,Y or Z key will datum that axis to zero.
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EXPERIMENT NO-6 Object:- To write and run the CNC program for the Milling Machine for the given drawing using CNC train simulator
Equipments Required:- Computer, CNC Milling Machine Theory:- A Part Program is a list of coded instructions which describes how the designed part, or component, will be manufactured. This part program is also called the CNC File. These coded instructions are called data - a series of letters and numbers. The part program includes all the geometrical and technological data to perform the required machine functions and movements to manufacture the part. The part program can be further broken down into separate lines of data, each line describing a particular set of machining operations. These lines, which run in sequence, are called blocks. A block of data contains words, sometimes called codes. Each word refers to a specific cutting/movement command or machine function. The programming language recognized by the CNC, the machine controller, is an International Standards Organisation code, which includes the G and M code groups. Each program word is composed from a letter, called the address, along with a number.
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Motion Command Codes:-
G CODES:- Set preparatory machine functions such as rapid transverse mode, feed mode and active tool length offsets. M CODES:- Perform a miscellaneous machine function such as automatic tool changes, coolant control and spindle operations.
Types of Formats:1. Tab Sequential Format 2. Fixed Format 3. Word Address Format PROGRAM BLOCK
Sequence Number (N)
Preparatory Word (G)
Tool Selection (T)
Spindle Speed (S)
Miscellaneous Command (M)
CAD/CAM LAB REPORT
Coordinates (X-Y-Z)
Feed Rate (F)
End of Block (E.O.B)
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For Example:- N10 GOO X30 Z-20 F10 S200 T01 M30
Steps in Programming:1. Start- work piece zero point, cutting speed, feed, spindle rotation, speed limit 2. Facing 3. Roughing
Process
4. Cutting 5. Close- stop spindle, stop coolant, program stop
FIGURE PROGRAM:CAD/CAM LAB REPORT
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T6 D6
; Center punching drill
bit G0 G90 G43 Z20 F200 S1800 M4 M8 M42 N10 G82 G99 X40 Y40 Z2 I-5 K300 N20 X-40 N30 Y-40 N40 X40 G80 G0 G44 Z100 T9 D9
; Drill bit
G0 G90 G43 Z20 F200 S1050 M4 M42 G81 G99 X40 Y40 Z2 I-35 X-40 Y-40 G0 G44 Z100 T8 D8
; Drill bit
G0 G90 G43 Z20 F200 S950 M4 M41 G81 G99 X-40 Y40 Z2 I-35 G0 X40 Y-40 CAD/CAM LAB REPORT
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G0 G44 Z100 T13 D13
; Reamer
G0 G90 G43 Z20 F100 S500 M4 M41 G85 G99 X-40 Y40 Z2 I-30 K200 X40 Y-40 G80 G0 G44 Z100 T12 D12
; Tap
G0 G90 G43 Z20 F450 S300 M4 M41 G84 G99 X40 Y40 Z2 I-35 K200 X-40 Y-40 G80 G0 G44 Z100 T2 D2
; End mill for
pockets G0 G90 G43 Z20 F250 S1600 M4 M42 N50 G87 G98 X0 Y0 Z2 I-5 J-30 K30 B5 D2 H200 L-1 N60 G88 G98 X0 Y0 Z-3 I-10 J-25 B5 D2 H200 L1
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G80 G0 G44 Z100 M30
QUESTION AND ANSWERS
Q1. What is the meaning of G17, G18, G19? Ans. G17-XY plane G18-XZplane G19- YZ plane Q2. What does M03, M04 stands for? Ans. M03-Spindle on (clockwise rotation) M04-Spindle on (counterclockwise rotation) Q3. Generally the CNC programming is written in which format? Ans. (a) Word Address Format (b) APT format Q4. What is the function of HOME command? Ans. Pressing the X,Y or Z key will send the machine to its home position along the selected axis. Q5. What is the function of DATUM command? Ans. Pressing the X,Y or Z key will datum that axis to zero
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